The explanation, in retrospect, is obvious: with System z10 on the horizon, major customers were deferring purchases of z9 BC or EC systems.

Now that System z10 is here, what will they do? As a rule, mainframe technologists are usually excited about each Big Iron update -- but how many will actually get a chance to put z10 through its paces in their own environments?

At this year's Winter SHARE conference, held last week in Orlando, attendees were given a unique opportunity to take System z10 for a test drive: IBM showcased a new z10 mainframe to the SHARE audience, and SHARE officials incorporated System z10 into several educational tracts or lab sessions. As a result, SHARE attendees got to tinker with the latest and greatest in mainframe silicon. What's more, many opted to have their photos snapped with Big Blue's new Big Iron system, according to SHARE officials.

"I have spent a bit of time over the last day and a half talking to some of my SHARE colleagues about [System z10]. There is strong interest. Some of our sessions here address this topic, and we handed out a sheet first thing Tuesday morning that had more than a dozen sessions listed about what was new, and then we he had a lab with an actual new z10 in it," explains SHARE president Martin Timmerman.

"The very first session on Tuesday morning was a lab with respect to running zLinux on a mainframe, and giving classmates the opportunity to bring up individual Linux machines on that architecture, so we got that all set up ahead of time." As SHARE president, Timmerman is no stranger to photo ops himself. Imagine his surprise, however, when attendees clamored for photos not with him, but with Big Blue's surprisingly diminutive z10 mainframe.

"There were a number of people who wanted their pictures taken beside it last night," he confirms. "As for its being a behemoth, I've been around the industry for an awful long time, and I can remember when we had a big room dedicated to big behemoths -- so, yes, this is much bigger than the ThinkPad I carry in my backpack, but it's not a behemoth, size-wise, at least."

Rank-and-file mainframe technologists are predictably excited about System z10. Consider Chuck Kreiter, a systems programming supervisor with a large insurance/financial services company that he asked not be named.) "I'm excited about the features announced with the z10. I expect when the 'Business Class' model is released, we will upgrade to it upon the end of lease for our z9," he says.

He cites a number of prospective benefits -- including IBM's MSU technology dividend, which typically grows stronger with each new revision of mainframe silicon. (http://esj.com/News/article.aspx?EditorialsID=2483) "In addition to the improvement in the MIPS/MSU arena, which will affect software costs, the speed of the processors will facilitate moving more CPU-intensive workloads from Windows to Linux running on zSeries."

Jim Melin, a systems programmer with a municipal government agency, says he's also excited about System z10. Melin's excitement is tempered, however; he says his organization won't ever deploy a z10. "We just put a z/9 on the floor, and while I'd like to see a z/10, zSeries here is dead. As soon as the legacy applications are gone, they'll be pulling the plug," he comments. "This might take four years still, but we're on the last mainframe this organization plans to buy, unless … [management] can be made aware of the virtualization benefits."

Jim Bohnsack, a z/VM programmer with Cornell University, is in a similar situation. Cornell, too, recently implemented a System z/9; they, too, plan to phase out the mainframe practice. "My employer … is on a 'get off the mainframe path' and has been 'working' in that direction since 1996," he says. "Now it appears that we may be there in three years or so. We will most likely not get a z10. About a year ago, we acquired a z9-BC, and that should last us through the next few years."

One of IBM's biggest pushes with System z10 is as a platform for server consolidation. Big Blue's z10 promotional collateral touted both its processing performance (equivalent to about 1,500 x86 systems) and power/cooling requirements (a fraction of the same) relative to standalone x86 servers. Users such as Bohnsack say that even though there's interest in virtualization and server consolidation in their environments, management isn't looking at the mainframe as a go-to consolidation platform.

"There is little interest in trying to consolidate servers onto the mainframe although there is certainly some Linux and VMWare interest," he observes. "I'm not in a position where I could make much of a difference in people's opinions," Bohnsack concludes, stressing, however, that he "would certainly be looking forward to moving to a z10" but that he's "afraid I will never see one."

In both Melin's and Bohnsack's cases, the decision to transition away from Big Iron was made long ago -- in Cornell's case, even prior to IBM's mainframe rebirth. For companies that aren't already executing on a long-term get-off-the-mainframe strategy, boosters say, System z10 has a compelling story -- particularly in the area of server consolidation, where its density, resiliency, and efficient power and cooling requirements far outstrip those of standalone x86 or of many RISC/Unix systems.

"I certainly do think [System z10] has a great consolidation story, and sometimes consolidations really work well and sometimes they're challenges. I think overall, we're seeing a number of consolidations, especially if people are going from Linux-based systems and Unix-based systems to run on zLinux, because the effort of any ports from those systems is not at all onerous," argues SHARE's Timmerman, who -- in his day job -- manages a heterogeneous data center environment of his own.

"For large customers -- and SHARE has a number of large customers that attend regularly -- it offers more capacity, more CPU capability, and more memory capability," he continues. "Every data center is having power and cooling challenges, and to have this kind of power in one footprint with the increases in capacity without much increase in power requirements really means you can get a lot more CPU capacity [with] less power consumption."

Although educational organizations such as Cornell might be moving away from Big Iron, other academic environments -- such as the University of Georgia (UGA) -- are boosting their mainframe investments. UGA, in fact, was a recipient of the 2008 SHARE Award for Excellence in Technology; it managed to decrease its operating expenses by upgrading to a 64-bit mainframe system and exploiting IBM's sub-capacity pricing metrics. UGA realized improvements in both performance and productivity and an attendant reduction in software costs, according to SHARE. The bottom line: UGA saved more than $1 million since going live on its implementation in December 2005.